One known means of obtaining electrical energy is a solar battery module comprising solar cells. Such solar battery modules are frequently disposed in locations where they are easily able to receive solar energy, such as on the roofs of buildings.
Consideration has been given to utilizing solar battery modules themselves as roof panels. In such cases, a roof with a power-generating function is constituted by covering the underlay material of the main structure of the roof of the building with the solar battery modules.
In a solar power-generating system using such solar battery modules, for example as shown in FIG. 17, a prescribed number of solar battery modules 101, . . . are mutually connected in series through output sections 104 on the back face thereof. A large number of series systems are obtained by connecting the solar battery modules disposed at the beginning and end of such series connections with connecting cables 108, 108 extending respectively indoors. In a typical system, the indoor electrical wiring is supplied by linking these with the commercial power system through an indoor inverter.
However, when covering the main structure of a roof with solar battery modules, it is demanded that a liquid-tight structure should be achieved wherein rainwater cannot invade to the back faces thereof from the gaps between adjacent solar battery panels and furthermore that installation should be easy. However, with the conventional method of installation, when the solar battery modules are utilized as roof panels, installation was carried out with the provision of sealing members between the ends of adjacent solar battery modules in the width directions intersecting the vertical direction of the roof along the eaves and the ridge.
However, if roof panels were installed providing sealing members between the ends of adjacent solar battery modules in this way, not only did this work take considerable time but also the waterproof condition was sometimes impaired at an early date owing to deterioration of the sealing members.
Also, solar battery modules of the type that are integral with building materials that are directly laid on a main roof structure in which an underlay sheet is provided on top of roof boards are laid with attention to rain sealing in particular so that rainwater cannot invade to the back face but, in order to cope with severe temperature differences on the roof, taking into account thermal expansion of the members, it is desirable to provide a gap of about 2 mm between the modules, for example between adjacent solar batteries and the supporting stand.
Under severe conditions of wind and rain, there is therefore the possibility of large amounts of rainwater invading from the gaps or damaged portions of the sealing; such rainwater invasion causes various problems at the back face of the solar battery modules. For example, accumulation of rainwater over a long period on the main roof structure may cause leakage of water into the building at this location or leakage of electricity and/or accumulated humidity may produce faults of the solar battery modules.